The request is from a PhD stdudent in France, he is developing some
distributed system based on libvirt, before deploying the codes to real
instances, he want to test it on his own box first.
Libvirt checks if it's migrating to same host by comparing the hostname,
I'm wondering if we can add some flag to switch the checking on/off,
(probally a new property in qemu.conf?), so that one can test the migration
on same host just for development purpose.

It isn't as simple as just removing the check, because libvirt also
checks other things like name+uuid uniqueness for the VMs. Also you
run the risk of deadlocking libvirtd itself
Daniel

If it's only one libvirtd process is running, it will deadlock itself, but
if one starts multiple libvirtd processes with different TCP/TLS port.
and do migration between those started libvirtd. It will work I guess.
But agree this is totally not productive, as it depends on user's
configuration, can intorduce many problems if one configured is not
expected.
Osier